chore(rollout): multiple minor improvements

src/lerobot/configs/dataset.py

@@ -69,7 +69,12 @@ class DatasetRecordConfig:
     # Lower values reduce CPU usage, maps to 'lp' (via svtav1-params) for libsvtav1 and 'threads' for h264/hevc..
     encoder_threads: int | None = None
 
-    def __post_init__(self) -> None:
+    def stamp_repo_id(self) -> None:
+        """Append a date-time tag to ``repo_id`` so each recording session gets a unique name.
+
+        Must be called explicitly at dataset *creation* time — not on resume,
+        where the existing ``repo_id`` (already stamped) must be preserved.
+        """
         if self.repo_id:
             timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
             self.repo_id = f"{self.repo_id}_{timestamp}"

src/lerobot/rollout/__init__.py

@@ -46,17 +46,25 @@ from .inference import (
     SyncInferenceEngine,
     create_inference_engine,
 )
-from .ring_buffer import RolloutRingBuffer
-from .robot_wrapper import ThreadSafeRobot
-from .strategies import RolloutStrategy, create_strategy
+from .strategies import (
+    BaseStrategy,
+    DAggerStrategy,
+    HighlightStrategy,
+    RolloutStrategy,
+    SentryStrategy,
+    create_strategy,
+)
 
 __all__ = [
+    "BaseStrategy",
     "BaseStrategyConfig",
     "DAggerKeyboardConfig",
     "DAggerPedalConfig",
+    "DAggerStrategy",
     "DAggerStrategyConfig",
     "DatasetContext",
     "HardwareContext",
+    "HighlightStrategy",
     "HighlightStrategyConfig",
     "InferenceEngine",
     "InferenceEngineConfig",
@@ -66,14 +74,13 @@ __all__ = [
     "RTCInferenceEngine",
     "RolloutConfig",
     "RolloutContext",
-    "RolloutRingBuffer",
     "RolloutStrategy",
     "RolloutStrategyConfig",
     "RuntimeContext",
+    "SentryStrategy",
     "SentryStrategyConfig",
     "SyncInferenceConfig",
     "SyncInferenceEngine",
-    "ThreadSafeRobot",
     "build_rollout_context",
     "create_inference_engine",
     "create_strategy",

src/lerobot/rollout/configs.py

@@ -89,8 +89,8 @@ class HighlightStrategyConfig(RolloutStrategyConfig):
     again.
     """
 
-    ring_buffer_seconds: float = 30.0
-    ring_buffer_max_memory_mb: float = 2048.0
+    ring_buffer_seconds: float = 10.0
+    ring_buffer_max_memory_mb: float = 1024.0
     save_key: str = "s"
     push_key: str = "h"
 

src/lerobot/rollout/context.py

@@ -346,6 +346,12 @@ def build_rollout_context(
                     "names": None,
                 }
 
+            if not cfg.dataset.repo_id.startswith("rollout_"):
+                raise ValueError(
+                    "Dataset names for rollout must start with 'rollout_'. "
+                    "Use --dataset.repo_id=rollout_<name> for policy deployment datasets."
+                )
+            cfg.dataset.stamp_repo_id()
             dataset = LeRobotDataset.create(
                 cfg.dataset.repo_id,
                 cfg.dataset.fps,

src/lerobot/rollout/strategies/core.py

@@ -267,7 +267,9 @@ def send_next_action(
     if interp is None:
         return None
 
-    action_dict = {k: interp[i].item() for i, k in enumerate(ordered_keys) if i < len(interp)}
+    if len(interp) != len(ordered_keys):
+        raise ValueError(f"Interpolated tensor length ({len(interp)}) != action keys ({len(ordered_keys)})")
+    action_dict = {k: interp[i].item() for i, k in enumerate(ordered_keys)}
     processed = ctx.processors.robot_action_processor((action_dict, obs_raw))
     ctx.hardware.robot_wrapper.send_action(processed)
     return action_dict

src/lerobot/rollout/strategies/dagger.py

@@ -693,6 +693,7 @@ class DAggerStrategy(RolloutStrategy):
             }
             # TODO(Steven): either enforce this (meaning all teleop must implement these methods) or
             # user is responsible for moving the teleop to the same position as the robot when starting the correction.
+            # Consider also a method that moves the robot to the teleop smoothly (similar to what we do at HW shutdown).
             # _teleop_smooth_move_to(teleop, robot_pos, duration_s=2.0, fps=50)
 
         elif new_phase == DAggerPhase.CORRECTING:

src/lerobot/rollout/strategies/highlight.py

@@ -22,7 +22,7 @@ import os
 import sys
 import time
 from concurrent.futures import Future, ThreadPoolExecutor
-from threading import Event as ThreadingEvent
+from threading import Event as ThreadingEvent, Lock
 
 from lerobot.common.control_utils import is_headless
 from lerobot.datasets import VideoEncodingManager
@@ -80,6 +80,7 @@ class HighlightStrategy(RolloutStrategy):
         self._push_requested = ThreadingEvent()
         self._push_executor: ThreadPoolExecutor | None = None
         self._pending_push: Future | None = None
+        self._episode_lock = Lock()
 
     def setup(self, ctx: RolloutContext) -> None:
         """Initialise the inference engine, ring buffer, and keyboard listener."""
@@ -168,7 +169,8 @@ class HighlightStrategy(RolloutStrategy):
                                 self._recording_live.set()
                             else:
                                 dataset.add_frame(frame)
-                                dataset.save_episode()
+                                with self._episode_lock:
+                                    dataset.save_episode()
                                 logger.info("Episode saved (total: %d)", dataset.num_episodes)
                                 log_say(
                                     f"Episode {dataset.num_episodes} saved",
@@ -198,7 +200,7 @@ class HighlightStrategy(RolloutStrategy):
                 logger.info("Highlight control loop ended")
                 if self._recording_live.is_set():
                     logger.info("Saving in-progress live episode")
-                    with contextlib.suppress(Exception):
+                    with contextlib.suppress(Exception), self._episode_lock:
                         dataset.save_episode()
 
     def teardown(self, ctx: RolloutContext) -> None:
@@ -268,12 +270,13 @@ class HighlightStrategy(RolloutStrategy):
 
         def _push():
             try:
-                if safe_push_to_hub(
-                    dataset,
-                    tags=cfg.dataset.tags if cfg.dataset else None,
-                    private=cfg.dataset.private if cfg.dataset else False,
-                ):
-                    logger.info("Background push to hub complete")
+                with self._episode_lock:
+                    if safe_push_to_hub(
+                        dataset,
+                        tags=cfg.dataset.tags if cfg.dataset else None,
+                        private=cfg.dataset.private if cfg.dataset else False,
+                    ):
+                        logger.info("Background push to hub complete")
             except Exception as e:
                 logger.error("Background push failed: %s", e)
 

src/lerobot/scripts/lerobot_record.py

@@ -394,6 +394,7 @@ def record(
                     "Dataset names starting with 'eval_' are reserved for policy evaluation. "
                     "lerobot-record is for data collection only. Use lerobot-rollout for policy deployment."
                 )
+            cfg.dataset.stamp_repo_id()
             dataset = LeRobotDataset.create(
                 cfg.dataset.repo_id,
                 cfg.dataset.fps,